Freitas J E, Sarosi M G, Nagle C C, Yeomans M E, Freitas A E, Juni J E
Department of Radiology, St. Joseph Mercy Hospital, Ann Arbor, Michigan 48106, USA.
J Nucl Med. 1995 Sep;36(9):1573-8.
To assess the use of modified PIOPED scintigraphic criteria for lung scan (V/Q) interpretation to detect pulmonary embolism (PE), we prospectively applied these criteria in suspected PE patients referred for V/Q from 9/1/92 to 2/7/94. PIOPED criteria were modified by placing a moderate segmental perfusion mismatch in the intermediate instead of low probability of PE category and using the "stripe sign."
Patients were studied by six-view V/Q imaging using 74 MBq (2 mCi) 99mTc-MAA followed by 148-370 MBq (4-10 mCi) 99mTc-DTPA aerosol, contrast pulmonary selective angiography and Doppler sonography with leg compression as needed. Patients underwent follow-up (mean 13.9 mo) to detect subsequent thromboembolic events. In this study group, 1000 patients were studied by V/Q followed by angiography in 133 patients.
The distribution of V/Q-assigned PE probabilities was: high probability 5.7%, intermediate 17.4%, low 41.4% and normal 35.5%. Group A patients (133) underwent angiography, which resulted in the determination of a 27.1% PE prevalence. Group B patients (867) did not have angiograms; the clinical prevalence of PE was 7.5%. In the total study population, the positive predictive value of a high probability V/Q study for PE (10.1% prevalence) was 98.2%, intermediate probability V/Q study for PE was 24.1% and a low probability study for PE was only 0.5%.
Modified PIOPED V/Q interpretation criteria afford better angioproven PE discrimination between intermediate (31.8% PE prevalence) and low (5.5% PE prevalence) probability V/Q results than reported for PIOPED intermediate (32.6% PE prevalence) and low (16.3% PE prevalence) probability V/Q interpretation criteria.
为评估改良的PIOPED肺扫描（V/Q）闪烁扫描标准在检测肺栓塞（PE）中的应用，我们于1992年9月1日至1994年2月7日对因V/Q检查而转诊的疑似PE患者前瞻性地应用了这些标准。PIOPED标准的改良方法是将中度节段性灌注不匹配置于PE可能性为中等而非低的类别中，并使用“条纹征”。
患者接受六视野V/Q成像检查，先静脉注射74MBq（2mCi）99mTc-MAA，随后吸入148 - 370MBq（4 - 10mCi）99mTc-DTPA气雾剂，必要时进行对比剂肺选择性血管造影及腿部压迫下的多普勒超声检查。患者接受随访（平均13.9个月）以检测后续血栓栓塞事件。在该研究组中，1000例患者接受了V/Q检查，其中133例患者随后接受了血管造影。
V/Q检查所确定的PE可能性分布为：高可能性5.7%，中等可能性17.4%，低可能性41.4%，正常35.5%。A组患者（133例）接受了血管造影，结果显示PE患病率为27.1%。B组患者（867例）未进行血管造影；PE的临床患病率为7.5%。在整个研究人群中，V/Q检查高可能性结果对PE的阳性预测值（患病率10.1%）为98.2%，中等可能性V/Q检查对PE的阳性预测值为24.1%，低可能性V/Q检查对PE的阳性预测值仅为0.5%。
与PIOPED标准中中等可能性（PE患病率32.6%）和低可能性（PE患病率16.3%）V/Q解释标准相比，改良的PIOPED V/Q解释标准在中等可能性（PE患病率31.8%）和低可能性（PE患病率5.5%）V/Q结果之间对血管造影证实的PE具有更好的鉴别能力。
